Recently, a display device using a mechanical shutter to which a MEMS (Micro Electro Mechanical Systems) technology is applied (hereinafter, such a shutter will be referred to as a “MEMS shutter”) is a target of attention. A display device using a MEMS shutter (hereinafter, referred to as a “MEMS display device”) opens or closes a MEMS shutter provided in correspondence with each of pixels, at a high speed by use of a thin film transistor (TFT), to control the amount of light to be transmitted through the shutter, and thus adjusts the brightness of an image (see, for example, Japanese Laid-Open Patent Publication No. 2008-197668). A mainstream gray scale system of such MEMS display devices is a time-ratio gray scale system of displaying an image by sequentially switching light provided from one of red, green and blue LEDs of an LED backlight unit to light provided from another LED of the LED backlight unit. Accordingly, the MEMS display devices have features that polarizing films or color filters used for a display device are not required; and as compared with a display device, the utilization factor of backlight is about 10 times higher, the power consumption is no more than half, and the color reproducibility is superior.
A MEMS display device is formed as follows. A TFT including switching elements for driving MEMS shutters, and gate and data drivers for driving the switching elements is formed on a substrate. Terminals for supplying signals from an external device to the TFT are also formed on the substrate. Usually for forming a MEMS display device, on the TFT substrate having the TFTs and the terminals formed thereon, a passivation film (insulating film) for covering the TFTs and the terminals is formed, and MEMS shutters are formed on the passivation film. An insulating film is formed to cover the MEMS shutters except for a part of each MEMS shutter which is to be electrically connected to a terminal. A movable section of the MEMS shutter has a hollow structure. Therefore, the insulating film is formed by CVD (Chemical Vapor Deposition) or the like on the entirety of a surface of the TFT substrate having the MEMS shutters formed thereon, so that a side surface and a bottom surface of the movable section is covered with the insulating film. Then, a counter substrate is joined to the TFT substrate. The terminals formed on the TFT substrate need to be supplied with signals from an external device. Therefore, the TFT substrate and the counter substrate are joined together such that the counter substrate does not cover a top surface of each terminal.
FIG. 10 is a schematic view of a pixel of a conventional MEMS display device. Elements of a display panel including a MEMS shutter on a TFT substrate adheres to the substrate or is deformed by static electricity. A spring structure formed of springs 8b connected to move the MEMS shutter is expanded or contracted by an electrical signal and thus moves a blocking section 8a of the MEMS shutter. A manufacturing process of the panel including a MEMS shutter on a power supply section (or wiring section) 1b of the TFT substrate includes a step of enclosing an insulating liquid such as silicone oil or the like to an area between the substrate having the MEMS shutter thereon and a counter substrate having a window. This step is carried out for the purpose of preventing the springs 8b connected to move the MEMS shutter from adhering to the TFT substrate having the MEMS shutter thereon or to the counter substrate having the window.
However, at the time of enclosure of the insulating liquid, static electricity is generated by friction of the liquid. Therefore, the MEMS shutter cannot be kept at a proper position or cannot be kept in a state of floating in the insulating liquid, and thus adheres to the substrate.
The present invention made in light of the above-described problem has an object of providing a display device and a method for manufacturing the same, for removing static electricity generated by friction at the time of enclosure of the insulating liquid and thus preventing a blocking section and springs of a MEMS shutter from adhering to the substrate or from being deformed.